HP Fortran Programmer's Guide (September 2007)

Porting to HP Fortran
Chapter 11232
In practice, however, programming is rarely so simple. Many Fortran programs have a long
history and were originally coded at a time when portability was not a concern because many
programs were written to execute on one platform only. Older Fortran programs—so-called
dusty-deck programs—are likely to have passed through different dialects of Fortran,
picking up features from each, even after those features have become outmoded. Porting
such a program may sometimes be as simple as identifying and removing the nonportable
features. But more often than not, it involves finding ways to implement the functionality of
the nonportable features.
To make the task of porting easier, HP Fortran includes the following features:
• Language extensions—statements, data types, directives, and intrinsic functions—that
are compatible with other Fortran implementations.
• Compile-line options to help with the porting process.
This chapter includes the following sections:
• Compatibility extensions
• Using porting options
NOTE For information about migrating HP FORTRAN 77 programs to HP
Fortran, refer to “Migrating to HP Fortran” on page 213.